Use of allograft bone matrix in clinical orthopedics

Clinical orthopedics continuously aims to improve methods for bone formation. Clinical applications where bone formation is necessary include critical long bone defects in orthopedic trauma or tumor patients. Though some biomaterials combined with autologous stem cells significantly improve bone repair, critical-size damages are still challenged with the suitable implantation of biomaterials and donor cell survival. Extracellular matrix (ECM) is the fundamental structure in tissues that can nest and nourish resident cells as well as support specific functions of the tissue type. ECM also plays a role in cell signaling to promote bone growth, healing and turnover. In the last decade, the use of bone-derived ECMs or ECM-similar biomaterials have been widely investigated, including decellularized and demineralized bone ECM. In this article, we reviewed the current productions and applications of decellularized and demineralized bone matrices. We also introduce the current study of whole limb decellularization and recellularization.

Preliminary Outcomes of a Staged Percutaneous Retrograde Prefabricated Gentamicin-coated Intramedullary Nail to Manage Complications after Ankle Fusion through Tibial Bone Transport

Aim

Distal tibial injuries combining bone loss, articular destruction and infection can be treated through distraction osteogenesis combined with ankle fusion. Bone transport is not without complications. This study investigates our preliminary results using a retrograde prefabricated gentamicin-coated nail (ETN PROtect®) to treat complications after infected bone defects of the distal tibial were managed by ankle arthrodesis and distraction osteogenesis.

Materials and methods

This is a retrospective case series study. All consecutive patients with bone transport complications after ankle arthrodesis and distraction osteogenesis who were subsequently operated on using a retrograde ETN PROtect® nail were analysed. The cases occurred between 2017 and 2020. The primary objective was to report on the resolution of the clinical problem and the risk of deep infection after nail implantation.

Results

Five patients have included: two docking site non-unions, two regenerated bone fractures and one hypotrophic regenerated bone. These complications were resolved in all patients (5/5, 100%). A painless, stable and plantigrade ankle arthrodesis was achieved in all cases. No patient developed a local infection or required nail removal (mean follow-up: 35.2 months). The mean LEFS score was 46.8 ± 13.8 and the mean knee ROM was 112 ± 12.7°. All patients tolerated full weight-bearing. All patients were very satisfied with the procedure (mean SAPS score was 93.8 points).

Conclusion

The staged retrograde nailing technique using the ETN PROtect® nail may represent an effective and safe treatment for bone transport complications in high-infection-risk patients. Furthermore, the technique allows simultaneous achievement of ankle arthrodesis. The patients had good functional outcomes and were satisfied with the procedure.

Clinical significance

This strategy of using retrograde gentamicin-coated tibial nails offers a solution to resolve bone transport complications while simultaneously achieving functional ankle arthrodesis.

How to cite this article

Pujol O, Vicente M, Castellanos S, et al. Preliminary Outcomes of a Staged Percutaneous Retrograde Prefabricated Gentamicin-coated Intramedullary Nail to Manage Complications after Ankle Fusion through Tibial Bone Transport. Strategies Trauma Limb Reconstr 2023;18(3):155-162.

Transporte sobre clavo respetando la membrana de Masquelet en defectos segmentarios severos. Serie de casos

Introducción: El adecuado tratamiento de los defectos óseos se presenta como un desafío para el cirujano ortopedista, en cuanto a la dificultad en la restitución de un miembro alineado, sin discrepancia ni infección. Se han descrito múltiples técnicas para reconstruir estos defectos, como el injerto óseo autólogo o de banco, la técnica de membrana inducida, la osteogénesis por distracción y los cilindros de titanio trabecular, pero ninguna ha demostrado ser significativamente superior a otra. Materiales y Métodos: Entre 2018 y 2021, 10 pacientes con defectos óseos de la tibia fueron tratados mediante transporte óseo guiado con osteosíntesis endomedular. Se realizó un estudio retrospectivo descriptivo analizando la magnitud de los defectos, el tiempo de transporte, las complicaciones y cirugías adicionales durante el proceso, si hubo consolidación y las deformidades residuales. Al final del proceso, se midió el puntaje de la ASAMI (óseo y funcional). Resultados: La longitud promedio de los defectos tratados fue de 9,75 cm y el índice de fijación externa promedio, de 40,62 días/cm. El 50% tenía un puntaje de la ASAMI óseo bueno; el 10%, excelente y el 40%, pobre al final del proceso reconstructivo. El 20% tenía un puntaje de la ASAMI funcional excelente; el 30%, bueno y el 50%, pobre. Conclusiones: El uso de tutores externos guiados mediante osteosíntesis es un método fiable para tratar defectos óseos, al mismo tiempo que se trata la infección de manera local y sistémica, acortando los tiempos de tutor externo y, por lo tanto, de internación y reintervención.

Progress on Biomimetic Mineralization and Materials for Hard Tissue Regeneration

Biomineralization is a process in which natural organisms regulate the crystal growth of inorganic minerals, resulting in hierarchical structured biominerals with excellent properties. Typical biominerals in the human body are the bones and teeth, and damage to these hard tissues directly affect our daily lives. The repair of bones and teeth in a biomimetic way, either by using a biomimetic mineralization strategy or biomimetic materials, is the key for hard tissue regeneration. In this review, we briefly introduce the structure of bone and tooth, and highlight the fundamental role of collagen mineralization in tissue repair. The recent progress on intra-/extrafibrillar collagen mineralization by a biomimetic strategy or materials is presented, and their potential for tissue regeneration is discussed. Then, recent achievements on bone and tooth repair are summarized, and these works are discussed in the view of materials science and biological science, providing a broader vision for the future research of hard tissue repair techniques. Lastly, recent progress on hard tissue regeneration is concluded, and existing problems and future directions are prospected.

Clinical and radiological assessment of the induced membrane technique using beta-tricalcium phosphate in reconstructive surgery for lower extremity long bone defects

AIMS

To clarify the effectiveness of the induced membrane technique (IMT) using beta-tricalcium phosphate (β-TCP) for reconstruction of segmental bone defects by evaluating clinical and radiological outcomes, and the effect of defect size and operated site on surgical outcomes.

METHODS

A review of the medical records was conducted of consecutive 35 lower limbs (30 males and five females; median age 46 years (interquartile range (IQR) 40 to 61)) treated with IMT using β-TCP between 2014 and 2018. Lower Extremity Functional Score (LEFS) was examined preoperatively and at final follow-up to clarify patient-centered outcomes. Bone healing was assessed radiologically, and time from the second stage to bone healing was also evaluated. Patients were divided into ≥ 50 mm and < 50 mm defect groups and into femoral reconstruction, tibial reconstruction, and ankle arthrodesis groups.

RESULTS

There were ten and 25 defects in the femur and tibia, respectively. Median LEFS improved significantly from 8 (IQR 1.5 to 19.3) preoperatively to 63.5 (IQR 57 to 73.3) at final follow-up (p < 0.001). Bone healing was achieved in all limbs, and median time from the second stage to bone healing was six months (IQR 5 to 10). Median time to bone healing, preoperative LEFS, or postoperative LEFS did not differ significantly between the defect size groups or among the treatment groups.

CONCLUSION

IMT using β-TCP provided satisfactory clinical and radiological outcomes for segmental bone defects in the lower limbs; surgical outcomes were not influenced by bone defect size or operated part. Cite this article: Bone Joint J 2021;103-B(3):456-461.

Unprecedented tibial bone lengthening of 33.5 cm by distraction osteogenesis for the reconstruction of a subtotal tibial bone defect. A case report and literature review

Background

We present a case of an immense unprecedented tibial bone lengthening of 33.5 cm. The management of chronic osteomyelitis of the right tibia with subtotal tibial bone defect, talus defect and equinus ankle deformity. We demonstrate limb reconstruction by distraction osteogenesis and correction of ankle deformity with the Ilizarov technique. Limb salvage was preferred as an alternative to amputation to restore basic limb function.

Case presentation

A 16-year-old male patient fell and injured his right lower leg. He attempted to treat the symptoms with traditional home remedies. During 15 months of self-treating, he developed osteomyelitis of the right tibia and had lost function in his foot. Radiology revealed immense bone defect of the right tibia, including talus bone defect and equinus deformity of the calcaneus. The patient’s right tibia was non weight-bearing, had drainage sinus just below his knee and a large scar anteriorly along the entire length of the tibia.

Conclusion

Upon completion of treatment, the patient was able to avoid amputation of his leg with partially restored function for weight-bearing. He carried himself without assistance after 3 years of lost function in his right leg. Tibial bone distraction osteogenesis of 33.5 cm was done after 90% of the tibial length was defected. To the best of our best knowledge, this case is one of a kind to achieve distraction of tibial bone to such length.

Polyetheretherketone and Its Composites for Bone Replacement and Regeneration

In this article, recent advances in the development, preparation, biocompatibility and mechanical properties of polyetheretherketone (PEEK) and its composites for hard and soft tissue engineering are reviewed. PEEK has been widely employed for fabricating spinal fusions due to its radiolucency, chemical stability and superior sterilization resistance at high temperatures. PEEK can also be tailored into patient-specific implants for treating orbital and craniofacial defects in combination with additive manufacturing process. However, PEEK is bioinert, lacking osseointegration after implantation. Accordingly, several approaches including surface roughening, thin film coating technology, and addition of bioactive hydroxyapatite (HA) micro-/nanofillers have been adopted to improve osseointegration performance. The elastic modulus of PEEK is 3.7-4.0 GPa, being considerably lower than that of human cortical bone ranging from 7-30 GPa. Thus, PEEK is not stiff enough to sustain applied stress in load-bearing orthopedic implants. Therefore, HA micro-/nanofillers, continuous and discontinuous carbon fibers are incorporated into PEEK for enhancing its stiffness for load-bearing applications. Among these, carbon fibers are more effective than HA micro-/nanofillers in providing additional stiffness and load-bearing capabilities. In particular, the tensile properties of PEEK composite with 30wt% short carbon fibers resemble those of cortical bone. Hydrophobic PEEK shows no degradation behavior, thus hampering its use for making porous bone scaffolds. PEEK can be blended with hydrophilic polymers such as polyglycolic acid and polyvinyl alcohol to produce biodegradable scaffolds for bone tissue engineering applications.

Submuscular plating of the femur through an anterior approach after bone distraction

The method of osteogenesis by distraction is a known technique in orthopaedics for the management of bone defects secondary to trauma, infections or tumours. New strategies have been developed for decreasing the external fixator time. The use of the minimally invasive plate osteosynthesis technique is a secure approach through a percutaneous fixation technique in the anterior aspect of the femur that permits minimal dissection of the soft tissues while preventing cross-contamination with the pin tracts of the external fixators. The goal of this article is to show that a new surgical technique, to preserve the benefits related to the internal fixation and at the same time decrease the risk of infection, can be used to perform femoral plating after bone distraction with a low contact plate through an anterior approach to the femur while still taking adequate care of the soft tissues.